Insulating sleeve for truck type oil switches



y 17, 1934- H. a. TAVERNER 1,967,014

INSULATING SLEEVE FOR TRUCK TYPE OIL SWI'I CHES Filed July 13, 1951 2Sheets-Sheet 1 July 17, 1934. H. B. TAVERNER 1,967,014

INSULATING SLEEVE FOR TRUCK TYPE OIL SWITCHES Filed July 13, 1931 2Sheets-Sheet 2 W Way's Patented July 17, 1934 1,961,014

UNITED STATES PATENT OFFICE INSULATING SLEEVE FOR TRUCK TYPE OILSWITCHES Howard B. Taverner, Chicago, 111.

Application July 13, 1931, Serial No. 550,409

Claims. (Cl. 173-28) My invention has reference broadly to procan beemployed repeatedly, and represents, tective appliances, and isspecifically concerned therefore, a device of standard character, ratherK with a novel insulating sleeve for encasing electhan a temporarymakeshift. trical conductors, particularly with a sleeve for The sleevewhich I have invented, and which'I use in connection with truck type oilswitches,- am about to disclose, is made of vulcanized rubtransformers,circuit breakers, and the like, deber. It is formed with a bias, tendingto curl signed and adapted to protect operators and othitself up tight,just as a piece of paper ,will tend ers from shock when working aroundor coming to do after it has been rolled up into a roll. The intocontact with such apparatus. sleeve is applied by pulling the edgesapart, pass- 10 The terminal studs of oil switches or transing it overthe connection which is intended to be formers are provided withsuitable connecting protected, and then allowing the ends to overlaplugs and similar lugs are attached to the cable each other by theresiliency of the material. conductors. These studs or lugs are providedfor The lower portion of the sleeve which engages the connecting thecable conductors with-the terinsulator or the bushing of the oil switchor minals of a switch. The lugs are joined by means transformer, etc.,may be provided with an inof clamping bolts or in another suitablemanner. terior shoulder to aid in maintaining the sleeve Such aconnection requires protecting provisions in position. The upper portionof the sleeve which on account of the high voltages which may be curlsaround the cable leading to the correspondtransmitted thereover, so thatoperators working ing terminal of the switch may be providedwith aroundthe apparatus; and other persons coming a ledge or lip if desired.

incidentally into contact therewith, might be When put in position, thenovel protecting sleeve protected against shock and possible injury.which I have described above in general terms, There are certain methodsknown for protectencloses the connections between a cable and a ingconnections of this type and of similar charterminal by attaching to theterminal bush- 25 acter. ing and to the insulation of the cable, re-

For example, one method proposes to rope and spectively. It providesthus a protective housto tape the lugs and the connections. This methingor casing around the connections, tapering 0d is very costly because itrequires several hours from the terminal bushing to the cable; andholdwork for cutting the. tape off from the terminals ing itself inposition by the resiliency oi the mate- 30 when an oil switch or thelike is to be opened rial and by the frictional qualities thereof. forperiodical cleaning and inspection. The nec- As has been saidpreviously, the sleeve is made essary .re-taping of the terminalconnections, of rubber. Ithas suflicient body to provide a seafter theswitch has been cleaned, increases the cure grip upon'the cable and uponthe terminal cost further and renders the method quite clumsy bushing,to maintain itself in position, particu- 35 if not entirely impractical.larly with the aid of the interior shoulder resting Another method su toProvide asbestos on the bushing. The bias which is formed on the guardsaround the connections. This latter sleeve material tends to secure itsresiliency and method is more in vog e. but it is ot e i y its qualityto roll itself tightly around even after satisfactory. Portions of thebare terminals and repeated use. The rubber may be strengthened by 40Connecting gs are exposed, nd h o itio textile fabric vulcanized in itif desired. represents a hazard and might lea to jury, The novelsleevecan be put in position and particularly in case of q p t which s pcan also be removed with great facility. It needs to public inspection.or which is Otherwise mad nospecial provisions for attachment, providesa accessible to inexperienced visitors. There are reliable protection,eliminates the need for as 45 cases known in which even maintenance menand bestos guards, taping or wrapping and the like,

operators were injured due to inadvertence or d i r safety around thapparatus or equip.- some unfortunate negelect, a fact which illust whiti l d, t, can be easily a trates clearly that a more permanent andmore f ct ed ith known processes nd m hi y complete protection isdesired and necessary than of r bbe goods pr duction a d c n b fu i h d50 is commonly employed. cheaply.

The Obj c y invention is to P id m- My invention secures thus an articlefor the proved protecting Sleeves for the p p Set reliable and completeprotection of electrical conforth above. The dGViCB which I disclose inthis actions of the type described, and of similar con- Specification isSimple in Construction t ay 'nections, and it secures this protection atless 5 be atta q y and Conveniently to a cost than it was necessary inthe past to expend nection between an oil switch and the like and forcumbersome appliances which furnished ina corresponding cable. and mayalso be removed complete protection or. pratically no protection withgreat facility. It is effective for its designed at all, since theseprior appliances were merely purpose, and will retain its position onsuch a of the character of temporary makeshifts, re-

60 connection without separatev securing means. It sorted to in theabsence of a permanent safety device especially designed for thepurpose. It will be understood, of course. that my protective sleeve mayalso be used for other equipment than the one which I have specificallymentioned. Examples of other uses to which my invention may be put willbe furnished later on.

I shall now describe the invention with reference to the accompanyingdrawings in which I have shown certain embodiments of the same in orderto teach others how the invention may be put to practical use.

In the drawings:

Figure 1 represents an elevational view into station equipment andillustrates particularly an oil switch with its terminal bushings andcables leading to the terminal of the switch, showing also protectingsleeves of the novel construction in connection with each cable and thecorresponding terminal bushing;

Figure 2 is a more diagrammatic partial side view into the equipmentsuch as shown in Figure 1, showing a truck type oil switch, cablesarranged above the oil switches adapted to connect with the terminalsthereof, and my novel protecting sleeves attached to the cables and tothe corresponding terminal bushings;

Figure 3 shows a longitudinal cross section through one embodiment ofthe novel insulating protecting sleeve as applied to a connectioncomprising a cableand a terminal bushing as well as the connectionsbetween the cable conductor and the lug projecting from the bushing;

Figure 4 is a transverse section through the cable taken on line 44 inFigure 3 and looking in the direction of the arrows;

Figure 5 is a transverse cross section through the arrangement taken online 5-5 in Figure 3 and looking in the direction of the arrows;

Figure 6 is a longitudinal cross section through another embodiment ofthe novel insulating sleeve similar to the view shown in Figure 3 butillustrating a different type of connection as well as a somewhatmodified type of sleeve; and

Figure 7 is a transverse cross section taken on line 7'7 in Figure 6looking in the directio of the arrows.

Referringnow to Figure l, I have shown in this figure a structuralframework comprising the vertical posts designated by numerals 1, 2 and3, two horizontal beams 4 and 5, and a cross support designated bynumeral 6. These beams and girders are part of a structural frameworkfor mounting oil switches and related station equipment in place. Theupper portion of a casing of such an oil switch, which may be of thetruck type, is shown in this drawing and designated by numeral 7.Terminal bushings which may be of insulating material, such as porcelainor the like, are mounted on the casing '7 by means of clampingprovisions such as 8, 9, 10, 11, 12 and 13. The insulating bushings aredesignated by numerals 14, 15, 16, 17, 18 and 19. Conductors rise fromthe interior of the oil switch within these bushings and each conductoris provided with a suitable lug. Cables such as indicated by thenumerals 20 to 25, inclusive, are provided for making connection withthe lugs of the individual conductors rising within the insulatingbushings from the oil switch. The end of each of the conductors of thesecables is also provided with a connecting lug or stud which is adaptedto be connected by clamping bolts or the like with the corresponding lugor stud of the respective conductor which extends from the correspondingbushing.

It is this connection of the bare conductors and parts, extending fromthe end of the con ductor of each cable to the conductor which risesfrom each of the insulating bushings, which must be protected in orderto prevent the transmission of shocks from these conducting parts to aperson working around the apparatus. In other words, it is the bareconductors disposed between the two insulating means (cable insulationand insulating bushing) which needs protection. The amount of work, whentaping or the like is resorted to, will be realized when it isconsidered that several oil switches might be disposed in a station,each having several terminals that need protection. The expenses for thetaping material are considerable and must be added to the expenses forthe work in order to gain a clear conception of the prevailingconditions.

In order to secure the necessary and desired protection of theseconnections I have provided my novel insulating protecting sleeves.These protecting sleeves are shown to be applied to the arrangementshown in Figure l and are indicated in this figure by the referencenumerals 26 to 31, inclusive. It will be seen that each sleeve isprovided with a bias which is molded into the material. In other words,each sleeve is treated so that when the sleeve is unwrapped it willspring back to the original position without any shaping by the hands.Each sleeve consists of a sheet of rubber suitably treated as indicatedabove in order to bias the material, and this sheet of rubber is simplypulled apart or unrolled, put around the parts to be protected and theedges are then released. The resiliency of the rubber will wrap thesheet around the oil switch connections in a manner as shown in thedrawings. The switch can then be made alive.

The lower end of each sleeve will attach tightly to the correspondingcable insulation. The connection between the cable conductor and theconductor rising from the insulating bushing will thus be securely andreliably protected and enveloped within the insulating sleeve.

The helical lines on the sleeves in Figs. 1 and 2 indicate how thesleeve may be made up of narrow strips of raw rubber wrapped upon asuitable form to give a conical shape. This is incidental and notessential, as the preferred form of the finished article exhibits asmooth exterior surface. By the term bias I mean to designate themechanical tendency which the finished sleeve has, to coil or roll uponitself. It will be seen that the sleeves are tapering, or of" conicalshape. This, of course, is a consequence of the particular use to whichthe sleeves are put in this case. I do not wish to limit the inventionto conical form only. The bushings, which are usually made of porcelainor like insulation of high grade, are of larger diameter than the-cablesand the tapering of the sleeves presents a neat appearance, beingdesigned in line and in harmony with the other parts. In a case in whichparts disposed between two insulating members of equal diameter are tobe protected, the sleeve will preferably be substantially cylin drical,and may have a shoulder at each end. It may also take other forms, suchas a spherical or bulbous form, if necessary.

Figure 2 will be easily understood from the previous remarks withreference to Figure 1. It shows a side view into a section of a stationhaving a structural framework which comprises vertically-disposed postssuch a 32 with pro visions for mounting the switch box such as 33 I andother apparatus. An oil switch of the truck type is shown at 34. Thisoil switch has the usual insulating bushings such as 35 and 36. Cablessuch as 3'7 and 38 are provided for making the connections from the oilswitch to certain connecting switches, such as the one indicated at 39which may be placed within the switch box 33. The connection betweeneach cable conductor and the corresponding conductor rising from the oilswitch is shown to be protected by means of my novel sleeves asindicated at 40 and 41. The connections are disposed within theseinsulating protecting sleeves as I have sketched in dotted lines. Eachconnection consists in this example of two lugs or studs, one attachedto the conductor of the cable and the other attached to the conductorrising from the corresponding insulating bushing of the oil switch. Inthe drawings, Figure 2, these connections are indicated in dotted linesdesignated by the reference numerals 42--43 and 44- 45, respectively.The nature of these connections will be better understood from a furtherdescription with reference to the remaining figures of the drawings.

Referring now particularly to the Figures 3, 4 and 5, which show severalcross sections taken on a structure on which my insulating sleeve hasbeen applied for protecting such a connection from an oil switch to acable, the numeral 46 designates the upper portion of an insulatingbushing which may be a part of an oil switch. A conductor 4'7 riseswithin the insulating bushing 46 from the interior of the oil switch andattached to this conductor 47 may be a connecting stud or lug such as48. The lug 48 may be provided with a threaded opening and the conductor4'7 may be provided with a threaded portion for engagement of theconnecting lug 48 as shown. The end of the cable is shown at 49. At 50 Ihave indicated the conductor of the cable, the insulation being removedfrom the end of this conductor in order to permit the conductiveconnection with the lug or stud 51 to be made.

- Each of the lugs 48 and 51 is provided with a flat portion indicatedby the reference numerals 52 and 53, respectively, and these flatportions of the lugs are brought into register with each other. Holesextend through each of the flat portions of the lugs and clamping boltssuch as 54 and 55 may be employed for fastening the lugs together, thebolts being held in position by means of suitable nuts such as 56 and5'7. This completes the conductive connection between the conductor 4'7of the oil switch and the conductor 50 of the cable 49. I

My novel insulating protecting sleeve is attached around the connectionby spreading and then allowing it to roll up around the connection intothe position previously described with reference to Figures 1 and 2. Thecross section in Figure 3 which is now-under discussion, shows moreparticularly how the sleeve is constructed and how the same attaches tothe insulating bushing and to the cable.

It will be seen from this Figure 3 that the lower portion of the sleeve,where the same attaches to the insulating bushing 46, is provided with aledge or interior shoulder designated by reference numeral '58. Thisshoulder is molded in the rubber sheet forming an integral part of thesleeve. It provides a means for positioning the sleeve quickly andaccurately, and also gives substantial body to the lower portion of thesleeve so that the sleeve in rolling around the insulating bushing 46will attach thereto, holding the sleeve tightly, and with a firm grip,on the bushing. The upper portion of the sleeve will attach to the cable49 as shown. This attachment is indicated by the layers 59 and 60 inFigure 3 which designate the inner portionof the sleeve as it is rolledaround the connection. The outer layers of the insulating sleeve aredesignated by the numerals 61 and 62. The bias which is molded into thematerial of the sleeve has not been indicated in Figure 3 because itwould unnecessarily confuse the drawings.

It will be observed that the lugs or studs 48 and 51, as well as themeans for connecting them in conductive relation, are entirely free, andencased within the insulating protecting sleeve. This shows that thesleeve has sufficient body to hold itself in position, self-supporting,without crushing in its intermediate portion.. It is held merely at theends, providing thus a hollow casing for the connection which isintended to be protected.

The transverse cross section shown in Figure 4 which is taken on lines4-4 in Figure 3, shows how the sleeve attaches to the cable 49. Theinner edge of the sleeve is designated in Figures 3, 4 and 5 by thenumeral 63. The outer edge of the sleeve is indicated by the numeral 64.g

In Figure 5, which is a transverse cross section taken on line 5-5 ofFigure 3, I have applied the same reference numerals to identical parts.The outer layers of the sleeve, corresponding to the layers shown inFigure 3, are designated by the numerals 61 and 62, while the innerlayers corresponding to the inner layers shown in Figure 3 are indicatedby the numerals 59 and 60. The interior shoulder which is provided inthe lower portion of the insulating sleeve and which attaches directlyto the insulating bushing 46 is designated by like reference numeral asin Figure 3. namely, by numeral 58. It will be seen that this shoulderextends only far enough to provide a suitable reinforcing portion and arest for the sleeve on the insulating bushing 46. Numeral 4'7 shows indotted lines the conductor disposed within the stud or lug 48. p

The embodiment which I have shown in Figures 6 and 7, the latter. figurebeing a transverse cross section taken on line 7-7 in Figure 6, showsthe application of my insulating protecting sleeve to a bushing andterminal of an oil switch of another type. This comprises an insulatingbushing 65 from which projects a threaded conductor 66, being fastenedby means of a suitable nut such as 67, and the conductor 66 beingprovided with the lug or stud 68, having a flat portion 69 which isbrought into register with a similar flat portion '70 of a stud '71fastened on the conductor '72 of the cable '73. The flat portions 69 and'70 of the studs 68 and '71 are clamped together by means of the bolts'74 and '75 held in place by the nuts '76 and '77 as shown. A washer ofmetal or insulating and preferably heat resisting material, such asasbestos, may be provided on top of the insulating bushing 65.

For bushing and terminal stud'constructions of the type wherein an ebonyasbestos washer of greater diameter than that of the bushing, rests uponthe top of the bushing, the lower end of my sleeve embraces theperiphery of the washer and the shoulder '78 or 58 of my sleeve restsupon the top margin of the washer. The sleeve thereby does not touch theporcelain or like insulation which constitutes the body of the bushing.

The protecting sleeve employed for the above nee-1,014

described connection between the cable '73 and the conductor 66 risingthrough the insulating bushing 65 may again consist of a rubber sheetcured or formed with an inherent bias to provide the required resiliencyand the tendency to roll up around the connection and attach itself onthe one end to the insulating bushing 65 and on the other end to thecable 73. This insulating protecting sleeve is provided in its lowerportion with an interior shoulder as is particularly indicated by thereference numeral '78 in Figure 6. This shoulder engages the upperportion of the insulating bushing 65 which may be either recessed orstepped down annularly or provided with a suitable insulating washer orthe like against which the interior shoulder 78 may rest in position.The upper portion of the insulating sleeve may be provided with areinforcing lip or bead such as indicated by the reference numeral 79.This lip or bead 79 will strengthen the upper edge of the insulatingsleeve which curls around the cable 73 and thus reinforced will causethe firm attachment of the sleeve to the cable in the manner shown.

The outer layer is indicated in the Figure 6 as well as in the Figure 7by the reference numerals 81 and 82, while the inner layer has beendesignated by the numerals 83 and 84. The numeral 85 in Figure '7indicates the longitudinal edge on the sleeve as attached to theconnection.

I have shown and described the invention in connection with embodimentsparticularly designed for use with oil switches and the like, forencasing the terminal connections between such switches andcorresponding cable conductors in order to afford a reliable'protectionto sub-station operators and to anyone who might come accidentally intocontact with such oil switch connections. It will be appreciated,however, that I have shown this specific form of realizing the inventionmainly for the purpose of explanation and not for the purpose ofindicating the limitations of the invention. The invention is manifestlycapable of being employed in connection with apparatus and machinery ofwidely different type and character. It may also be employed forencasing and for reliably protecting electrical connections which areeither of a delicate nature or for other-reasons in need of protectionagainst mechanical injury, or electrical contact, or both.

Inasmuch as the invention discloses novel and useful aspects apart fromthe specific use to which I have shown the same to be applied, it willbe understood that I do not desire to be limited to this preciseembodiment but that I desire to employ and to exploit the invention inall such embodiments and for all such uses as may fall within the scopeand meaning of the appended claims. I have defined in these claims WhatI believe to be new and what I desire to have protected by LettersPatent.

I claim:-

1. A sleeve for enclosing electrical connections, said sleeve comprisingresilient insulating material rolled upon itself to form a tapered tubeof larger diameter at one end than at the other, the inner and outerlongitudinal edges of the tube being free of interfering projections topermit uncoiling of the tube against its natural resiliency, and topermit a natural recoiling of the same to fit, and grip at its two ends,an object to be shielded, the large diameter end of the tube beingthickened and provided with an internal shoulder for centering the tubeand supporting the same in position.

2. In combination, electrical apparatus including an enclosing casing,an insulating bushing extending from the casing, a conductor extendingoutward of the casing through the bushing, a terminal at the end of thebushing terminating the conductor that extends through the bushing, asecond conductor extending to said terminal and connected thereto toestablish connections with the first mentioned conductor, and a taperedtubular shield surrounding the terminal and extending from the bushingto the conductor and comprising a resilient insulating tubing splitlengthwise to permit opening of the same for removal and insertionaround the terminal, and having an inherent inward coiling whereby thesame tends to resume and maintain its tubular form, the wide end of saidtubing embracing the bushing and including an internal shouldersupporting the tubing and centering it around the terminal, the narrowend of the tubing encircling the second mentioned conductor and grippingthe same by the inherent resiliency of the tubing, the contraction ofthe tubing at the two ends being limited by the respective objectsembraced whereby the tubing is firmly held in place.

3. In combination, electrical apparatus including an enclosing casing,an insulating bushing extending from the casing, a conductor extendingoutward of the casing through the bushing, a terminal at the end of thebushing and terminating the conductor that extends through the bushing,a second conductor extending to said terminal and connected thereto toestablish connection with the first mentioned conductor, and a tubularshield surrounding the terminal, said shield extending from the bushingto the second conductor and comprising a resilient insulating tubingsplit lengthwise to permit opening of the same for removal and insertionaround the terminal, and having an inherent inward coiling whereby thesame tends to resume and maintain its tubular form, one end of saidtubing embracing the periphery of said bushing and including an internalshoulder supporting the tubing and centering it on the bushing andaround the terminal. Y

4. In combination, a bushing having a terminal conductor projectingtherethrough, a second conductor adapted to be connected to saidterminal conductor, said bushing being of greater diameter than saidsecond conductor, and an insulating shield for enclosing the connectionbetween said conductors extending from said bushing to said secondconductor, said shield comprising a coiled helical strip with adjacentturns overlapping to form a resilient tubing adapted to be opened forremoval and application around said connection and having an inherentinward coiling tendency whereby the shield tends to coil itself aroundthe periphery of said bushing and around said second conductor.

5., In combination, a pair of conductors adapted to be connectedtogether, a bushing enclosing one of said conductors adjacent saidconnection, and a resilient insulating shield member formed of a coiledhelical strip adapted to enclose said connection and adapted to beopened for lateral removal and application about said connection, saidshield member having an inherent inward coiling tendency whereby saidmember tends to embrace the peripheries of said bushing and the otherone of said conductors to support said member in position.

HOWARD B. TAVERNER.

